If this ruling were to stand, once could see an enormous impact, as although neither carrier sells unlimited plans any longer, grandfathered users on AT&T and Verizon do have unlimited plans still in place. Those users are subject to throttling, but AT&T throttles if a user is in the "top 5 percent." Verizon only throttles if the specific cell tower a "heavy user's" phone is communicating with is congested at that moment.
T-Mobile throttles when a customer oversteps his data tier, which means customers know exactly when they will be throttled. Sprint does not throttle, and is the only of the Big 4 U.S. wireless carriers to have both unlimited and unthrottled data.
That may not be such a bad deal, however. Last month, Heather Peters won a small claims court lawsuit against Honda over its mileage claims for its Civic Hybrid. If she had joined a class action against the company, the best she could have done was between $100 and $200 and a $1,000 rebate coupon toward the purchase of a new Honda.
To determine AT&T's "penalty," Judge Nadel looked at the remaining 10 months in Spaccarelli's two-year contract with AT&T and estimated that he might pay an average of $85 a month for using additional data if he were on a tiered plan (AT&T charges $10 for every extra GB over 3GB).
Considering the possibility that Spaccarelli's victory might spur others to also file claims against AT&T, it's quite possible that AT&T will appeal. In fact, AT&T spokesman Marty Richter told AP that the carrier was "evaluating" the possibility.